<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        *{margin:0;padding:0}
        div{
            width:100px;
            height:200px;
            background: red;
            /* transform:rotate(90deg); */
            transition:all 1s;
            transform-origin: right bottom;
        }
        div:hover{
            transform:rotate(0deg)
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>